Direct Observation of Surface State Thermal Oscillations in SmB<sub>6</sub> Oscillators

ORAL

Abstract

SmB6 is a mixed valence Kondo insulator that has been proposed to be a topological Kondo Insulator with a Kondo insulating gap in the bulk and a gapless Dirac state on the surface. Exploiting its non-linear dynamics, a tunable SmB6 oscillator device was recently demonstrated, where a small DC current generates large oscillating voltages at frequencies from a few Hz to hundreds of MHz. This behavior was explained by a theoretical model describing the thermal and electronic dynamics of coupled surface and bulk states. Here we report direct measurements of the time-dependent surface state temperature in SmB6 with a RuO2 micro-thermometer. Our results agree quantitatively with the theoretically simulated temperature waveform, and hence support the validity of the oscillator model, which will provide accurate theoretical guidance for developing future SmB6 oscillators at higher frequencies.

*This work is supported by NSF grants DMR-1350122 and DMR-1708199

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Presenters

  • Brian Casas

    • Department of Physics and Astronomy, Univ of California - Irvine

Authors

  • Brian Casas

    • Department of Physics and Astronomy, Univ of California - Irvine

  • Alexander Stern

    • Department of Physics and Astronomy, Univ of California - Irvine

  • Dmitry Efimkin

    • University of Texas at Austin
    • Department of Physics, University of Texas - Ausin
    • Univ of Texas, Austin

  • Jing Xia

    • Physics and Astronomy, Univ of California - Irvine
    • Department of Physics and Astronomy, Univ of California - Irvine
    • University of California Irvine
    • Department of Physics, University of California, Irvine
    • Department of Physics and Astronomy, University of California, Irvine

  • Zachary Fisk

    • Physics and Astronomy, University of California
    • Department of Physics and Astronomy, Univ of California - Irvine
    • Department of Physics and Astronomy, University of California - Irvine
    • University of California Irvine
    • University of California, Irvine
    • Physics, University of California
    • Los Alamos National Laboratory
    • Department of Physics, University of California
    • Physics, University of California, Irvine
    • Department of Physics and Astronomy, University of California, Irvine